The Hunt and Hess classification is used to evaluate the severity of a subarachnoid hemorrhage, providing a risk assessment of mortality based on specific signs and symptoms. Here's how it works:

For each symptom description, a numerical score is assigned:

- Asymptomatic, or minimal headache and slight nuchal rigidity: 1
- Moderate to severe headache, nuchal rigidity, and possibly cranial nerve deficit (missing from input, typically score is 2)
- Drowsiness, confusion, or mild focal deficit: 3
- Stupor, moderate-to-severe hemiparesis, possibly early decerebrate rigidity, vegetative disturbances: 4
- Deep coma, decerebrate rigidity, moribund appearance: 5

Once the symptoms are categorized and the score is determined, it translates directly to a corresponding grade and associated mortality risk. Here's the interpretation based on scores:

- A score of 1 indicates Grade I; the individual is asymptomatic or has only minimal symptoms, with a 1.4% risk of mortality.
- A score of 2 reflects Grade II, where symptoms like moderate to severe headache and nuchal rigidity are present, with a 5.4% mortality risk, though specific details for this score were missing.
- A score of 3 corresponds to Grade III, marked by drowsiness or mild focal deficits, and carries an 18.8% risk of mortality.
- A score of 4 is Grade IV, characterized by stupor and possible moderate-to-severe hemiparesis, with a 41.9% mortality risk.
- A score of 5 translates to Grade V, indicating severe symptoms such as deep coma and a moribund appearance, with a 76.9% risk of mortality.

This systematic approach allows for a structured assessment of the severity of a subarachnoid hemorrhage by processing a patient's symptoms into a score that aligns with standard health outcomes.

The Hunt and Hess Classification of Subarachnoid Hemorrhage is a clinical grading system used to assess the severity of subarachnoid hemorrhage. This calculator is applicable to patients who have experienced a subarachnoid hemorrhage, which is a type of stroke caused by bleeding in the space surrounding the brain. 

The clinical utility of the Hunt and Hess classification is to predict the prognosis and guide the management of patients with subarachnoid hemorrhage. It helps clinicians to estimate the risk of mortality and morbidity, and to decide on the most appropriate treatment strategy. 

The classification ranges from Grade I (asymptomatic or minimal headache and slight nuchal rigidity) to Grade V (deep coma, decerebrate rigidity). Higher grades are associated with worse prognosis.

There are no specific exclusion criteria for the use of the Hunt and Hess classification. However, it may not be as accurate in patients with other concurrent severe medical conditions or in those who have received treatment prior to grading.

Hunt and Hess classification of subarachnoid hemorrhage